The present invention relates to barriers for preventing vehicles from travelling along predetermined paths.
Thus, as is well known, parking spaces for vehicles may be assigned to given individuals, so that only a vehicle of an authorized individual is intended to occupy a given parking space. In order to assure that the space is not occupied by an unauthorized vehicle, the rightful occupant will normally be able to place a barrier across the space when the authorized individual leaves the space in an unoccupied condition.
Thus, while arrangements of the above type are indeed well known, the conventional arrangements suffer from several drawbacks. For example, in order to economize a suitable upright with a pair of barrier arms suspended therefrom may conventionally be located at every other boundary line between a row of parking spaces, so that with this arrangement the barrier arms are swung up to blocking positions with a pair of barrier arms extending toward each other from a pair of successive uprights in order to block entrance to a pair of adjoining spaces situated between the pair of uprights. However, because of limitations in the possible height of the upright from which the barrier arms hang and because of limitations in the weight of the swingable barrier arm which is generally made of a heavy metal, such conventional barrier arms can only be made of a limited length. Therefore when they are in their blocking positions they extend only through a relatively small extent across a given parking space with the result that the free ends of a pair of barrier arms which project toward each other from a pair of successive uprights leave between themselves a space large enough for a vehicle to enter between the barrier arms which are in their blocking positions. In order to prevent movement of a vehicle into this space between such a pair of barrier arms, it is conventional to provide at the boundary lines which alternate with those where the uprights are located posts which thus become situated at every boundary line between a pair of successive uprights. With such posts in position of course a vehicle cannot then enter into the space between a pair of barrier arms which extend toward each other from a pair of successive uprights and which are in their blocking positions. However, such a conventional arrangement creates certain problems which are peculiar thereto. When the barrier arm is in a non-blocking position giving access to a given parking space, the vehicle must travel between an upright and the post at the adjoining boundary line, and for reasons of economy, the parking spaces are made only sufficiently wide to accommodate a conventional vehicle, so that a considerable amount of skill is required in order to drive a vehicle accurately into a parking space between an upright and a post. As a result of this arrangement, when a vehicle is not driven into a parking space with the required skill it becomes located to close to an upright or a post, causing a considerable amount of inconvenience by requiring people to squeeze through the narrow space between a post or upright and the vehicle, and indeed it is not uncommon for a vehicle to strike against a post or upright with such conventional arrangements.
Furthermore, because the barrier arms must of necessity extend through a given minimum distance to prevent access to a given parking space when the barrier arm is in its blocking position, it is essential to make an upright and an arm hanging therefrom of a given minimum length. The result is that even while making a barrier arm as short as possible nevertheless it weighs a substantial amount, requiring exertion of relatively powerful forces in order to raise the barrier arm to its blocking position, and indeed weak individuals such as women, children, or elderly people have encountered difficulty in swinging the barrier arm from its non-blocking to its blocking position.
Barriers of the above general type have created special problems at the entrance to a given area as the entrance to a large parking area where a barrier arm is situated in order to prevent unauthorized individuals from entering into the parking area. Such barrier arms are of necessity relatively large and considerable force is required to swing them between their blocking and nonblocking positions, bearing in mind that under these conditions the barrier arm must be repeatedly swung between its positions a large number of times since such barrier arms are situated at the entrance to the parking area. All of the cars which occupy the parking area will necessarily move through the entrance, and thus such barriers encounter a considerable amount of wear and use due to their repeated movement between blocking and non-blocking positions, and in addition it is difficult to move such arms because of the weight thereof.